1. Field of the Invention
The present invention relates to a CBCM (Charge-Based Capacitance Measurement) circuit using a CBCM technique, and a capacitance measurement technique using the CBCM circuit.
2. Description of the Background Art
The CBCM circuit is a capacitance measurement circuit with sub-fF (10−15 F or less) sensitivity that is difficult to achieve with AC current meters such as an LCR meter with sufficient accuracy, and is disclosed in James C. Chen et. al., “An On-Chip Attofarad Interconnect Charge-Based Capacitance Measurement (CBCM) Technique,” IEDM Technical Digest, 1996, pp. 69–72. Further, an improved CBCM circuit that is capable of separately measuring parts of capacitance in an interconnect configuration is disclosed in U.S. Pat. No. 6,300,765.
In the conventional and improved CBCM circuits, a measuring target capacitance is predetermined; for example, a total capacitance or parts of capacitance in an interconnect configuration, etc. Thus, it is difficult to separately measure each component of the measuring target capacitance.